PROJECT SUMMARY/ABSTRACT There is a relative lack of efficacious behavioral weight control interventions for adolescents from low-income backgrounds. Although, developmentally, adolescence is marked by profound psychosocial and physiological stressors, none of the available behavioral weight control interventions have included a primary focus on stress reduction. Chronic stress may interfere with weight management through biological (e.g., HPA activation resulting in cortisol disruption) and behavioral (e.g., emotional eating) mechanisms. Growing literature supports mindfulness interventions for youth outcomes. Mindfulness-Based Stress Reduction holds promise to improve standard behavioral weight control (SBWC) in low-income adolescents but has not been adapted for adolescent weight management- demonstrating both the novel and innovative nature of the proposed study. This gap in the literature is notable given that mindfulness interventions have been 1) shown to yield desirable changes in obesity-related eating behaviors (e.g., emotional eating) among adults, 2) successfully adapted for adolescents, and 3) shown to yield changes in biological indicators of stress (cortisol, salivary ?-amylase [sAA]) tied to obesity and eating. The proposed study is designed to conduct early development, feasibility testing, and refinement of a group-based mindfulness augmented behavioral weight management intervention, with a focus on decreased emotional eating, in low-income obese adolescents (ages 13-17). A 16-week, group mindfulness based weight control (MBWC) intervention will be adapted across Phases 1a and 1b to focally target emotional eating and improve weight management outcomes. In Phase 1a, a youth advisory board will be engaged to assist in integrating principles of Mindfulness-Based Stress Reduction with SBWC. The initial acceptability and feasibility of MBWC will then be evaluated in an open trial with n=16 low-income, obese adolescents for further refinement of intervention content. During Phase 1b, n=60 low-income, obese adolescents will be randomized to receive either MBWC or SBWC. Participants will complete assessments before and after treatment. Aim 1 is to determine the feasibility and acceptability of the adapted MBWC intervention via the pilot trial (Phase 1a) and preliminary randomized trial (Phase 1b). Measures will include retention through the 16-week intervention, attendance, completion of weekly food monitoring logs, and treatment acceptability. Aim 2 (Phase 1b, randomized trial) is to estimate the effect size of MBWC relative to SBWC on proximal mechanisms, including emotional eating and levels of daily and chronic stress, as indicated by both stress-sensitive biomarkers (salivary cortisol, sAA) and subjective report. Aim 3 (Phase 1b, randomized trial) is to estimate the effect size of MBWC relative to SBWC in decreasing absolute and zBMI from baseline to end-of-treatment. This study will help initiate a line of research broadly examining how to improve behavioral weight management and reduce pediatric obesity health disparities in low-income adolescents by applying a novel mindfulness-based intervention.